Just for clarification, nearly every class C ever built has had a fridge that can run on propane or 110V and some will run on 12V also... just like a TC. If you compare a TC with a propane genny versus a C with a gasoline powered genny, the TC's genny will burn through the propane pretty fast. This means that if you want to run a TC genny for air conditioning, you would like to have far more propane capacity than you would every need with a C. The way around this for a TC is to use a portable genny running on gasoline but then you need to store it and you might need two of them to run AC. If you consider the furnace, a TC furnace will need less propane than a C simply because there's a lot less space to heat. Sadly, every RV choice has its pros and cons and you have to pick what works for your style of travel and camping.